diff --git a/.github/workflows/validate-skills.yml b/.github/workflows/validate-skills.yml
new file mode 100644
index 0000000..e8e7c32
--- /dev/null
+++ b/.github/workflows/validate-skills.yml
@@ -0,0 +1,16 @@
+name: Validate Skills
+
+on:
+  pull_request:
+  push:
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Validate skill catalog
+        run: bash ./scripts/validate_skills.sh
diff --git a/.gitignore b/.gitignore
index e43b0f9..b24428d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .DS_Store
+.worktrees/
diff --git a/README.md b/README.md
index 024c5d4..112713d 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ Portable Elixir and Phoenix skills for Codex.
 
 This repository packages custom skills from a local Codex setup so they can be installed on any machine into `~/.codex/skills`.
 
+Each install writes a manifest of the skills this repository manages. Future installs use that manifest to prune skills that were removed from the repo without touching unrelated skills in the target directory.
+
 ## Included
 
 - Elixir/Phoenix skills under [`skills/`](skills/)
@@ -44,6 +46,8 @@ git pull
 ./install.sh
 ```
 
+If a previously installed skill has been removed from this repository, a subsequent install prunes it automatically by consulting the stored manifest.
+
 ## Uninstall
 
 ```bash
@@ -62,6 +66,14 @@ Custom target:
 CODEX_HOME=/path/to/.codex ./uninstall.sh
 ```
 
+## Validate
+
+```bash
+bash ./scripts/validate_skills.sh
+```
+
+This checks the skill catalog for broken local `references/...` links and verifies the install and uninstall scripts, including the guarantee that `install.sh --dry-run` leaves the filesystem untouched.
+
 ## Acknowledgment
 
 Inspired by [oliver-kriska/claude-elixir-phoenix](https://github.com/oliver-kriska/claude-elixir-phoenix). This repository is a Codex-oriented adaptation and is not an official fork.
diff --git a/install.sh b/install.sh
index 69b0f5a..1d300d4 100755
--- a/install.sh
+++ b/install.sh
@@ -13,32 +13,51 @@ EOF
 
 DRY_RUN=0
 
-case "${1:-}" in
-  --dry-run)
-    DRY_RUN=1
-    ;;
-  "" )
-    ;;
-  -h|--help)
-    usage
-    exit 0
-    ;;
-  *)
-    usage
-    exit 1
-    ;;
-esac
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      DRY_RUN=1
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      usage
+      exit 1
+      ;;
+  esac
+
+  shift
+done
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SOURCE_DIR="$REPO_ROOT/skills"
 CODEX_HOME="${CODEX_HOME:-$HOME/.codex}"
 TARGET_DIR="$CODEX_HOME/skills"
-
-mkdir -p "$TARGET_DIR"
+MANIFEST_PATH="$TARGET_DIR/.codex-elixir-phoenix-manifest"
 
 echo "Source: $SOURCE_DIR"
 echo "Target: $TARGET_DIR"
 
+list_source_skills() {
+  find "$SOURCE_DIR" -mindepth 1 -maxdepth 1 -type d | sort
+}
+
+skill_in_list() {
+  local needle="$1"
+  shift
+  local skill_name
+
+  for skill_name in "$@"; do
+    if [[ "$skill_name" == "$needle" ]]; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
 copy_skill() {
   local skill_name="$1"
   local source_path="$SOURCE_DIR/$skill_name"
@@ -54,6 +73,45 @@ copy_skill() {
   echo "installed $skill_name"
 }
 
+prune_removed_skills() {
+  local skill_name
+  local target_path
+
+  if [[ ! -f "$MANIFEST_PATH" ]]; then
+    return
+  fi
+
+  while IFS= read -r skill_name; do
+    [[ -z "$skill_name" ]] && continue
+
+    if skill_in_list "$skill_name" "${SOURCE_SKILLS[@]}"; then
+      continue
+    fi
+
+    target_path="$TARGET_DIR/$skill_name"
+
+    if [[ "$DRY_RUN" -eq 1 ]]; then
+      echo "[dry-run] prune $target_path"
+      continue
+    fi
+
+    if [[ -d "$target_path" ]]; then
+      rm -rf "$target_path"
+      echo "pruned $skill_name"
+    fi
+  done < "$MANIFEST_PATH"
+}
+
+write_manifest() {
+  if [[ "$DRY_RUN" -eq 1 ]]; then
+    return
+  fi
+
+  printf '%s\n' "${SOURCE_SKILLS[@]}" > "$MANIFEST_PATH"
+}
+
+SOURCE_SKILLS=()
+
 while IFS= read -r skill_path; do
   skill_name="$(basename "$skill_path")"
 
@@ -61,8 +119,20 @@ while IFS= read -r skill_path; do
     continue
   fi
 
+  SOURCE_SKILLS+=("$skill_name")
+done < <(list_source_skills)
+
+if [[ "$DRY_RUN" -ne 1 ]]; then
+  mkdir -p "$TARGET_DIR"
+fi
+
+prune_removed_skills
+
+for skill_name in "${SOURCE_SKILLS[@]}"; do
   copy_skill "$skill_name"
-done < <(find "$SOURCE_DIR" -mindepth 1 -maxdepth 1 -type d | sort)
+done
+
+write_manifest
 
 if [[ "$DRY_RUN" -eq 1 ]]; then
   echo "Dry run complete."
diff --git a/scripts/validate_skills.sh b/scripts/validate_skills.sh
new file mode 100644
index 0000000..6ba974b
--- /dev/null
+++ b/scripts/validate_skills.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+SKILLS_DIR="$REPO_ROOT/skills"
+TEMP_DIRS=()
+ERRORS=0
+
+cleanup() {
+  local dir
+
+  for dir in "${TEMP_DIRS[@]}"; do
+    if [[ -d "$dir" ]]; then
+      rm -rf "$dir"
+    fi
+  done
+}
+
+trap cleanup EXIT
+
+make_temp_dir() {
+  local dir
+
+  dir="$(mktemp -d "${TMPDIR:-/tmp}/codex-elixir-phoenix.XXXXXX")"
+  TEMP_DIRS+=("$dir")
+  printf '%s\n' "$dir"
+}
+
+record_error() {
+  echo "ERROR: $*" >&2
+  ERRORS=$((ERRORS + 1))
+}
+
+list_source_skills() {
+  find "$SKILLS_DIR" -mindepth 1 -maxdepth 1 -type d | sort
+}
+
+validate_skill_references() {
+  local skill_dir
+  local skill_file
+  local ref
+
+  while IFS= read -r skill_dir; do
+    skill_file="$skill_dir/SKILL.md"
+
+    if [[ ! -f "$skill_file" ]]; then
+      record_error "$(basename "$skill_dir") is missing SKILL.md"
+      continue
+    fi
+
+    while IFS= read -r ref; do
+      [[ -z "$ref" ]] && continue
+
+      if [[ ! -f "$skill_dir/$ref" ]]; then
+        record_error "$(basename "$skill_dir") references missing file: $ref"
+      fi
+    done < <(rg -o 'references/[A-Za-z0-9._/-]+' "$skill_file" | sort -u || true)
+  done < <(list_source_skills)
+}
+
+validate_dry_run_is_clean() {
+  local sandbox
+
+  sandbox="$(make_temp_dir)"
+  CODEX_HOME="$sandbox" "$REPO_ROOT/install.sh" --dry-run >/dev/null
+
+  if [[ -e "$sandbox/skills" ]]; then
+    record_error "install.sh --dry-run created $sandbox/skills"
+  fi
+}
+
+validate_install_round_trip() {
+  local sandbox
+  local manifest_path
+  local skill_dir
+  local skill_name
+
+  sandbox="$(make_temp_dir)"
+  manifest_path="$sandbox/skills/.codex-elixir-phoenix-manifest"
+
+  CODEX_HOME="$sandbox" "$REPO_ROOT/install.sh" >/dev/null
+
+  if [[ ! -f "$manifest_path" ]]; then
+    record_error "install.sh did not write the ownership manifest"
+  fi
+
+  while IFS= read -r skill_dir; do
+    skill_name="$(basename "$skill_dir")"
+
+    if [[ ! -d "$sandbox/skills/$skill_name" ]]; then
+      record_error "install.sh did not install $skill_name"
+    fi
+  done < <(list_source_skills)
+
+  CODEX_HOME="$sandbox" "$REPO_ROOT/uninstall.sh" >/dev/null
+
+  if [[ -f "$manifest_path" ]]; then
+    record_error "uninstall.sh did not remove the ownership manifest"
+  fi
+
+  while IFS= read -r skill_dir; do
+    skill_name="$(basename "$skill_dir")"
+
+    if [[ -e "$sandbox/skills/$skill_name" ]]; then
+      record_error "uninstall.sh did not remove $skill_name"
+    fi
+  done < <(list_source_skills)
+}
+
+validate_skill_references
+validate_dry_run_is_clean
+validate_install_round_trip
+
+if [[ "$ERRORS" -gt 0 ]]; then
+  echo "Validation failed with $ERRORS error(s)." >&2
+  exit 1
+fi
+
+echo "Skill catalog validation passed."
diff --git a/skills/elixir-phoenix-compound/SKILL.md b/skills/elixir-phoenix-compound/SKILL.md
index bc1d459..05077dd 100644
--- a/skills/elixir-phoenix-compound/SKILL.md
+++ b/skills/elixir-phoenix-compound/SKILL.md
@@ -50,8 +50,8 @@ existing** (same root cause, new symptom), or **Skip**.
 Extract from session context: module, symptoms, investigation
 steps, root cause, solution code, and prevention advice.
 
-Validate frontmatter against `compound-docs/references/schema.md`,
-then create file using `compound-docs/references/resolution-template.md`.
+Open `elixir-phoenix-compound-docs` and use its schema and
+resolution template references before writing the solution file.
 
 ### Step 4: Decision Menu
 
@@ -86,4 +86,4 @@ When user says "that worked", "it's fixed", "problem solved",
 ## References
 
 - `references/compound-workflow.md` — Detailed step-by-step
-- See also: `compound-docs` skill for schema and templates
+- See also: `elixir-phoenix-compound-docs` for schema and templates
diff --git a/uninstall.sh b/uninstall.sh
index b95ac53..4006b17 100755
--- a/uninstall.sh
+++ b/uninstall.sh
@@ -13,30 +13,37 @@ EOF
 
 DRY_RUN=0
 
-case "${1:-}" in
-  --dry-run)
-    DRY_RUN=1
-    ;;
-  "" )
-    ;;
-  -h|--help)
-    usage
-    exit 0
-    ;;
-  *)
-    usage
-    exit 1
-    ;;
-esac
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      DRY_RUN=1
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      usage
+      exit 1
+      ;;
+  esac
+
+  shift
+done
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SOURCE_DIR="$REPO_ROOT/skills"
 CODEX_HOME="${CODEX_HOME:-$HOME/.codex}"
 TARGET_DIR="$CODEX_HOME/skills"
+MANIFEST_PATH="$TARGET_DIR/.codex-elixir-phoenix-manifest"
 
 echo "Source: $SOURCE_DIR"
 echo "Target: $TARGET_DIR"
 
+list_source_skills() {
+  find "$SOURCE_DIR" -mindepth 1 -maxdepth 1 -type d | sort
+}
+
 remove_skill() {
   local skill_name="$1"
   local target_path="$TARGET_DIR/$skill_name"
@@ -54,15 +61,37 @@ remove_skill() {
   fi
 }
 
-while IFS= read -r skill_path; do
-  skill_name="$(basename "$skill_path")"
+OWNED_SKILLS=()
 
-  if [[ "$skill_name" == ".system" ]]; then
-    continue
-  fi
+if [[ -f "$MANIFEST_PATH" ]]; then
+  while IFS= read -r skill_name; do
+    [[ -z "$skill_name" ]] && continue
+    OWNED_SKILLS+=("$skill_name")
+  done < "$MANIFEST_PATH"
+else
+  while IFS= read -r skill_path; do
+    skill_name="$(basename "$skill_path")"
+
+    if [[ "$skill_name" == ".system" ]]; then
+      continue
+    fi
 
+    OWNED_SKILLS+=("$skill_name")
+  done < <(list_source_skills)
+fi
+
+for skill_name in "${OWNED_SKILLS[@]}"; do
   remove_skill "$skill_name"
-done < <(find "$SOURCE_DIR" -mindepth 1 -maxdepth 1 -type d | sort)
+done
+
+if [[ -f "$MANIFEST_PATH" ]]; then
+  if [[ "$DRY_RUN" -eq 1 ]]; then
+    echo "[dry-run] remove $MANIFEST_PATH"
+  else
+    rm -f "$MANIFEST_PATH"
+    echo "removed manifest"
+  fi
+fi
 
 if [[ "$DRY_RUN" -eq 1 ]]; then
   echo "Dry run complete."